U.S. Provisional Application No. 61/277,758, filed Sep. 29, 2009, is incorporated herein by reference in its entirety.
With the demand for energy contained in biomass, demand for equipment to harvest the biomass has increased dramatically. This has thus created a need for modifications to equipment that has existed in the marketplace, as well as for completely new equipment. Some of the challenges that must be overcome include the loading, moving, transporting and refining the harvested biomass. Additionally, in some instances, it may be desired that some of the biomass created in a harvesting operation be returned to the field. This can be for any of a number of reasons, including, but not limited to, to prevent erosion, to break down and return nutrients to the field, and because those aspects of the biomass are insufficiently valuable to justify costs of collection, storage and/or transportation to a user. Particularly with regard to corn, such unwanted biomass can include shucks or husks that wrap about the corn ears, leaf trash from the corn stalks, as well as the stalks themselves. In contrast, the corn cobs and fodder associated with the cobs is considered valuable, both as animal feed, and as sources of oil and fuel.
As an example, presently there is an increased demand for cobs as a feedstock for cellulosic ethanol. As a result, there is heightened interest in collecting corn cobs during corn harvest. There is also concern by some that cob collection may reduce soil nutrient content. In this regard, crop residue or stover, e.g., corn stalks, leaves, husks and cobs, are traditionally left on the field after harvest, and break down over time to replenish soil nutrients. If a component of the stover, e.g., cobs is instead collected, nutrient levels could be lowered as a result. To mitigate this concern, some consider it desirable when collecting cobs, to collect mostly just the cobs, that is, with substantially all loose or detached residual elements of the residue, which are lighter than the cobs, mainly, husks and leaves and fragments thereof, returned to the field.
Thus, it is sought to have a biomass conveyor system adapted for operation in connection with a harvester, and optionally a collection device for the heavier or denser more valuable biomass to be gathered, which incorporates an ability to separate or remove other lighter crop residue or stover, and return the other lighter residue to the field in a distributed manner.
Numerous apparatus have been proposed for use in connection with biomass conveying devices, particularly for cobs, for cleaning or separating other stover and crop residue from the cobs and distributing or spreading it. To illustrate, prior to the early 1960's, the common corn harvesting practice involved picking the ears of corn in the field, removing husks from the ears, and transporting the ears still containing the corn kernels to a corn crib, and later shelling the corn off of the cobs at a stationary sheller. This harvesting procedure has been almost entirely replaced by modern self-propelled combine type harvesters, which use a threshing and separating system to separate and collect the corn kernels, and discharge the cobs and other stover onto the field.
Combines which harvest the corn and separate the kernels from the cobs and other stover or residue, then discharge the cobs and other stover onto the field, are now the industry standard. More recently, devices for collecting cobs discharged from combines have been developed. Several of such known devices have variously utilized a towed cart or wagon for receiving and holding the cobs, and a conveyor system for conveying the cobs from the combine to the cart or wagon. Some of the cob collection devices also include apparatus for separating the cobs from the lighter other stover or residue downstream or remotely from the combine, mainly using air flow. Reference in this regard, Flamme U.S. Pat. No. 5,941,768, issued Aug. 24, 1999, which discloses a cob collection unit pulled behind a combine to collect on a first conveyor all the residue discharged from the combine, with a separation unit behind the conveyor including a second conveyor, and utilizing a fan to suck the lighter stover from the cobs as they are released from the top of the second conveyor and to blow the stover back onto the field. Redekop et al. U.S. Patent Publication Nos. 20090095662 published Apr. 16, 2009; 20090104952 published Apr. 23, 2009; and 20090124309 published May 14, 2009, disclose a pulled cob collection unit, which utilizes a sequential series of inclined belt conveyors, and blower or suction fans disposed remotely from the combine for directing air through the discharged material as it falls from the upper end of one conveyor onto a lower end of the next conveyor, such that the heavier cobs are to continue to the next conveyor and the lighter stover or residue will be carried away by the air flow, with the cobs being conveyed into a collection tank by a further conveyor or conveyors.
An observed shortcoming of the above referenced known cob conveyor and distributing systems, is a lack of utilization of available air flow discharged from the cleaning system of a harvester, which air flow can be quite voluminous and powerful, even after it has left the harvester.
Thus, what is sought is a biomass conveying and distributing system for use in association with a harvester such as a combine, which provides one or more of the capabilities set forth above, namely, effective separating and distributing of lighter other crop residue from the wanted heavier or denser biomass, e.g., cobs, utilizing available apparatus and capabilities found on a harvester, namely, air flow from the cleaning system of the harvester, while minimizing shortcomings of known devices and systems, namely, increased apparatus, weight, complexity and power demand of a trailer towed by the harvester.